Labour's trade spokesman and a former Trade Minister Phil Goff says he understands why the Government is not releasing text of the Trans Pacific Partnership agreement but says it could be doing more to communicate with New Zealanders.

His position is more moderate than that of new Labour leader David Cunliffe, a former diplomat, who called on the Government to release the draft text on his first day in the job.

Mr Goff picked up trade from Clayton Cosgrove in Mr Cunliffe's reshuffle, after losing his prized foreign affairs portfolio to his former protégé and former leader David Shearer.

Mr Goff was Foreign Minister for six years in the fifth Labour Government and Trade Minister for three in which he concluded the China free trade agreement with New Zealand.

Asked for a response to the online campaign by some New Zealand celebrities to release draft text of the TPP, Mr Goff said that would probably not be possible.

The 12 parties would have an agreement that the text could not be revealed.

"You probably can't breach that agreement but what you can do and what the Government hasn't done is broadly spell out its negotiating position," he told the Herald.

"The TPP itself has the potential to provide huge benefits to New Zealand; it also raises issues that are of deep concern to a lot of New Zealanders such as whether it would override the ability of the Government to legislate for the public good in health and the environment.

"What I think it is incumbent for the Government to do, as I did with China, is just spell out your positions very clearly about the things you will be fighting tooth and nail either for or to prevent."

Mr Goff told the Herald he favoured a comprehensive agreement for the TPP - meaning no products to be exempted for the removal of tariffs over time.

"If you don't have a comprehensive agreement the first thing that the vested interest groups in Japan, Mexico, Canada and the United States - which are our four target markets in this agreement - will want to do is excluded dairy, and then they'll probably want to exclude meat. Then some of them will want to exclude horticulture and at the end of it, you've gained nothing. " Prime Minister John Key, who is chairing a meeting of TPP leaders in Bali today, rejected Mr Goff's criticism.

"I don't think that is right. I think we have made very strongly the case that firstly we are not going to sign a deal unless it is in New Zealand's interests.

"Second we expect the deal to be comprehensive which includes everything but there will be phase-in times.

"Thirdly on the best estimates we have at the moment, there is huge economic uplift for New Zealand and that modelling shows anything between $2.1 billion to $4 billion a year."

It depended a lot on the phase-outs, what the deal looks like, what compromises New Zealand needed to make.

He said a small group was opposed to the TPP but they were opposed to the China FTA and to free trade generally.

"I don't that is consistent with the view of the public. I think the New Zealand public generally speaking have seen the benefits of free trade."